The Definition and Measurement of Dangerous Research
Total Page:16
File Type:pdf, Size:1020Kb
Center for International and Security Studies at Maryland The Definition and Measurement of Dangerous Research Alex Greninger July 2004 CISSM School of Public Policy This paper was prepared as part of the Advanced Methods of Cooperative Security Program at 4113 Van Munching Hall the Center for International and Secuirty Studies at Maryland, with generous support from the University of Maryland John D. and Catherine T. MacArthur Foundation. College Park, MD 20742 Tel: 301-405-7601 [email protected] Outline I. Introduction to the Biological Research Security System Model A. The 3-D Definition of Danger 1. Define Transmissibility 2. Define Infectivity 3. Define Lethality B. Defining the Project At Hand C. Where Do Candidate Pathogens Fit into the Danger Terrian? II. Influenza A. Parameter Background 1. Transmissibility 2. Lethality 3. Infectivity B. Highlighting Problematic Research That Has Been Done 1. General Pathogenesis 2. Determinants of 1918 Influenza Pathogenesis 3. Determinants of H5N1 Virus Pathogenesis C. Highlighting Problematic Research That Could Be Done D. Difficulties in Creating an Oversight System for Influenza Research E. Recommendations for Influenza Research III. Pneumonic Plague A. Parameter Background 1. Transmissibility 2. Infectivity 3. Lethality 4. Conclusions B. Highlighting Problematic Research That Has Been Done 1. Increasing Presentation or Activity of Virulence Factors 2. Therapy and Prophylaxis Resistance C. Highlighting Problematic Research That Could Be Done D. Conclusions IV. Conclusions A. Recommendations 1. Include Countermeasures 2. Build the Science of Transmissibility 3. Recognize the Threat Presented By Host Susceptibility and Immunology 4. Keep Weaponization Information Under Control 5. Is Infectivity Useful? B. Long-Term Dilemmas 1. The Host-Pathogen Relationship 2. Signaling Danger? 3. Dealing With Agents Under the Radar 2 I. Introduction to the Biological Research Security System Model Both scientists and policy-makers are increasingly recognizing the potential and pitfalls of biotechnology in regards to biosecurity. The spread of biotechnology and biological research across the globe is revealing a great deal of information on the origins of human disease and microbial pathogenesis. There is great hope that the genetic, proteomic, and metabolomic information will yield new antimicrobial and immunological therapies and vaccines in upcoming years. However, continued research into disease pathogenesis also has the potential to cause more harm than good without proper oversight. Although such a negative experimental outcome has not manifested itself yet, recent experiments into mouse host susceptibility to an engineered strain of mousepox and a smallpox complement inhibitor have pointed the way toward the need for greater debate, if not oversight, of scientific research into high-threat pathogens.1 Mindful of the possible threat of this “scientific inadvertence,” security studies experts at the University of Maryland have proposed a legally binding, global oversight system to deal with the threat presented by advanced pathogens.2 The so-called Biological Research Security System (BRSS) does not seek to ban any research. Rather, the BRSS wishes to develop legally enforceable “protective standards of prudence” by mandating independent peer review to assess not only the scientific merit and biosafety/physical security protocols for the research, but also its larger social consequences. Given the recent explosive growth in biodefense research funding and the access limitations to pathogen stocks based on nationalities, the lack of true research oversight is especially glaring. One of the chief problems in devising such a system is coming up with a definition of dangerous research that captures relevant research without being unduly broad and sets clear, consistent standards for managing high-consequence research without being arbitrary or excessively rigid. As originally conceived in "Controlling Dangerous Pathogens: A Protective Oversight System," the BRSS would match the expected level of risk involved in proposed research with the level and extent of oversight that it would receive. The risk level would reflect three epidemiological parameters intrinsic to each pathogen -- transmissibility, infectivity, and lethality -- and would consider the probability that proposed research activities would significantly increase the level of danger on one or more of these dimensions. Figure 1 shows a three-dimensional conceptual scheme in which “potentially” dangerous research is reviewed only at the local level, “moderately” dangerous research is reviewed also at the national level, and “extremely” dangerous research is raised to the international level of oversight (qualitatively noted as the green, yellow, and red areas). 1 Cozzarelli, NR. “PNAS policy on publication of sensitive material in the life sciences,” Proceedings of the National Academy of Sciences 100(4) (18 February 2003): 1463. 2 Steinbruner, J. E.D. Harris, N. Gallagher, and S. Gunther. “Controlling Dangerous Pathogens: A Prototype Protective Oversight System,” Center for International Security Studies at Maryland Working Paper (September 2003), esp. pp. 19-25. Available at http://ww.cissm.umd.edu/documents/pathogensmonograph.pdf. 3 Figure 1 - 3D Danger Space Figures 2-4 give illustrative lists of research activities that might fit into each oversight category. Figure 2 - Potentially Dangerous Activities Overseen by Local BRSS Committees Figure 3 - Moderately Dangerous Activities Overseen by National BRSS Committees 4 Figure 4 - Extremely Dangerous Activities Overseen by International BRSS Committees A list-based approach to defining danger has the advantage of being more concrete and less ambiguous than the conceptual scheme. However, depending on how the list is structured, lists of candidate research activities can be excessively narrow in some regards, overly broad in others, and quickly outdated in a rapidly evolving field. Furthermore, while the list-based definition of dangerous research makes it easy to match proposals with the appropriate level of review, it provides the reviewers with little guidance as they try to assess the benefits and risks of a given proposal. Therefore, this paper examines the literature on two high-threat pathogens, influenza and pneumonic plague, to assess the operational difficulty of defining dangerous research in terms of standard quantitative measures for transmissibility, infectivity, and lethality. A. The 3-D Definition of Danger While no three parameters can capture the entire picture of what makes an infectious agent unique and dangerous, transmissibility, infectivity, and lethalty present a great deal of the basic biology of a pathogen. 1. Defining Transmissibility Transmissibility is defined as the ease with which an organism spreads from person-to- person. It should not be confused with the ability of an organism to spread from the dispersion device to the index cases, or infectivity. Assuming an organism is reasonably pathogenic, transmissibility can be considered the most critical parameter in the pyramid definition of danger. It is what separates the ability of biological weapons to be a true weapon of mass destruction versus a special type of one-off bomb that has historically yielded mostly mass disruption. Epidemiologists do not have standard ways of measuring the intrinsic transmissibility of pathogens. Transmissibility is also rarely quantified due to the difficulties in contact tracing and the relative novelty of epidemic modeling that takes into account contact tracing. Traditionally, transmissibility has been represented by R0, or basic reproduction number, in epidemiological models. R0 is defined as the number of cases that one case will directly infect when introduced into an entirely susceptible population. Although this definition works in a bioterror context – most populations would be entirely susceptible to bioterror agents – R0 has the major drawback in research oversight of integrating the intrinsic biology of a pathogen with the circumstance of its release. The same organism may have different R0’s depending on whether it is released in a closed building or an open field. R0’s measured inside buildings, usually hospital wards, typically overestimate the true transmissibility of the organism because contacts in hospitals are necessarily very close and often; patients are often already sick or immunocompromised; and hospital personnel often aid in the spread of the disease around a ward. R0 can be determined in two different ways. The method used most often involves the use * * of seroprevalance data; R0 = 1/x where x is the fraction susceptible at equilibrium. This fraction can be estimated via seroprevalence data. The other method is far more laborious. R0 = τcδ, where 5 τ is the transmissibility of the pathogen; c is the average contact rate in the population; and δ is the expected time of removal from the infected population (from recovery). A measure for intrinsic transmissibility does exist (τ), but it is somewhat difficult to calculate. This subject will be covered in further detail in the concluding chapter. For most epidemiologists, the combination of social and pathogenic factors in R0 is of little to no consequence. Epidemiologists are chiefly concerned with the propagation and possible elimination of an epidemic. Environmental conditions of an outbreak may be relevant to the control of future outbreaks. R0 captures the entirety of an epidemic and greatly